[yansong] #2 Add sync and async job to show difference.
[yansong] #2 Add sync and async job to show difference.

Cuiyansong/Why-To-Use-Async-Await-In-DotNet,Cuiyansong/Why-To-Use-Async-Await-In-DotNet,Cuiyansong/Why-To-Use-Async-Await-In-DotNet